arping: fix iface name in error messages

arping: interface eth0 not found: No such device
                  ^^^^

This is because error template is formed before parsing command line arguments,
so it always uses default interface name "eth0".

Signed-off-by: Alexander Korolkov <alexander.korolkov@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
1 file changed